1. Field of the invention
This invention concerns an automatic reverse method for reversing the black-and-white monochrome image on a display, and a printer unit using the same method, specially a printer unit used in a plant operation. More specifically, it concerns an automatic reverse method for automatically reversing the received black-white monochrome image into the white-black monochrome image under predetermined condition. This method and printer unit is used for a monochrome image data transmitted from a process controller in a power plant or other plant.
2. Description of the Invention
Let us assume that data from a process control device are displayed on the monitor screen of an operation device, and that the content displayed on the monitor screen of the operation device is to be printed. Let us further assume that the printer to be used is a black-and-white (monochrome) printer, and that it prints the display exactly as it is. If a large proportion of the screen is black, the white portions of the resulting printout will be damaged, and it will be difficult or impossible to read correctly.
This problem is addressed in the prior art by having a human operator manually check the proportion of the black-and-white monochrome images on the monitor screen before printing what is shown on the monitor. He would then manually determine whether to reverse the black-white monochrome image into the white-black monochrome image or leave it alone, and he would submit the appropriate print command.
As is shown in FIG. 6, it is very common for prior art process control devices in a plant to be set up so that operation device 10 and printer 12 are physically separated from each other. When the content on monitor screen 11 of operation device 10 is to be printed by printer 12, the operator first checks the display to see if it has too much of a black component. If it does, he pushes button 15 on printer 12 to indicate that the black-and-white components of the monochrome image should be reversed. He then presses print button 14 on operation device 11 to request printing. Thus the operator has to perform two separate tasks before printing: 1) he must check the proportion of black to white areas on monitor 11, and 2) he must actuate the black-and-white reversal button on printer 12. He cannot simply start the printing operation.
The operator has to use the monitor display each time he wishes to print in order to judge whether to reverse the black-and-white components. This complicates the task and is a source of potential human error.
The objective of this invention is to provide an automatic reverse method for reversing and displaying the black-white monochrome image into the white-black monochrome image under the predetermined condition, and a printer unit using the same method, specially a printer unit used in a plant operation. According to this invention, it would allow the printing operation to be accomplished merely by actuating a print button on operation device 10. The judgment of whether to reverse the black-and-white components, which was the responsibility of the operator in the prior art design, would be made automatically, and the human errors would be eliminated.
This invention discloses a method to automatically reverse a received black-and-white monochrome image of control data into a white-and-black monochrome image, and displaying the received or reversed monochrome image on a display monitor. The black-and-white monochrome image includes both a black or relatively darker monochrome portion, and a white or relatively lighter monochrome portion in the received monochrome image. It is characterized by the following configuration. The method has a step of:
1) calculating the proportion of the black or relatively darker monochrome portion among the received black-and-white entire monochrome image;
2) judging whether or not the proportion of black or relatively darker monochrome portion exceeds a given value or not; and
3) controlling the displayed monochrome image, displaying either said received black-and-white monochrome image without any reversal if said proportion does not exceed said given value, or the reversed white-and-black monochrome image if the proportion exceeds the given value. In the reversed image, the black or relatively darker monochrome portion is replaced with the white or relatively lighter color in the white or relatively lighter monochrome portion, and the white or relatively lighter monochrome portion is replaced with the black or relatively darker color in the black or relatively darker monochrome portion.
This invention also discloses a print control device to automatically reverse a received black-and-white monochrome image of control data into a white-and-black monochrome image, and displaying the received or reversed monochrome image on a display monitor. The black-and-white monochrome image includes both a black or relatively darker monochrome portion, and a white or relatively lighter monochrome portion in the received monochrome image. The print control device comprises:
1) a calculating means to calculate the proportion of the black or relatively darker monochrome portion among the received black-and-white entire monochrome image;
2) a judging means to judge whether or not said proportion of black or relatively darker monochrome portion exceeds a given value or not; and
3) a controlling means to control the displayed monochrome image, displaying either the received black-and-white monochrome image without any reversal if the proportion does not exceed said given value, or the reversed white-and-black monochrome image if the proportion exceeds the given value. In the reversed image, the black or relatively darker monochrome portion is replaced with the white or relatively lighter color in the white or relatively lighter monochrome portion, and the white or relatively lighter monochrome portion is replaced with the black or relatively darker color in the black or relatively darker monochrome portion.
This invention further discloses a printer to print a monochrome image data provided with an automatic reversal device to automatically reverse a received black-and-white monochrome image of control data into a white-and-black monochrome image. The black-and-white monochrome image includes both a black or relatively darker monochrome portion, and a white or relatively lighter monochrome portion in the received monochrome image. The printer comprises:
1) a raster memory having an equal capacity for one frame of a monitor screen, which stores a bitmap of a control data to be displayed on a display monitor;
2) a counting means to count the number of pixels indicated by xe2x80x9c1xe2x80x9d or xe2x80x9c0xe2x80x9d in the bitmap;
3) a judging means to judge whether or not the proportion of the counted number of pixels among the received black-and-white entire monochrome image exceeds a given value or not; and
4) a controlling means to control the displayed monochrome image, displaying either the received black-and-white monochrome image without any pixel reversal in said bitmap if the proportion does not exceed the given value, or the reversed white-and-black monochrome image in which each pixel is reversed between xe2x80x9c1xe2x80x9d and xe2x80x9c0xe2x80x9d if the proportion exceeds the given value.
This invention further disclosed a printer specially used for plant operation. It prints a monochrome image data, and is provided with an automatic reversal device to automatically reverse a received black-and-white monochrome image of control data into a white-and-black monochrome image. The black-and-white monochrome image includes both a black or relatively darker monochrome portion, and a white or relatively lighter monochrome portion in the received monochrome image. The printer comprises:
1) a calculating means to calculate the proportion of the black or relatively darker monochrome portion based on a plant information and the background image information;
2) a judging means to judge whether or not the proportion of black or relatively darker monochrome portion exceeds a given value or not; and
3) a controlling means to control the displayed monochrome image, displaying either the received black-and-white monochrome image without any reversal if the proportion does not exceed the given value, or the reversed white-and-black monochrome image if the proportion exceeds the given value. In the reversed image, the black or relatively darker monochrome portion is replaced with the white or relatively lighter color in the white or relatively lighter monochrome portion, and the white or relatively lighter monochrome portion is replaced with the black or relatively darker color in the black or relatively darker monochrome portion.
As will be shown in the embodiment to follow, the reversal means to control the reversal of the image may be realized either by software or by hardware.
With this invention mentioned above, when the operator actuates a print command, the operation device in and of itself can control the black-and-white reversal and produce a print. The operator no longer needs to check the display screen and determine whether to reverse the black-white image into the white-black image before printing.